Material for packaging a moisture-sensitive product, a process for the manufacture of such material, and packaging comprising such material

Abstract

A packing material, generally in sheet form, is made from a combination of a support sheet and a water-retentive material that is intimately connected to the support sheet. Moisture or exudate originating from a product enclosed by the packing material is absorbed and retained by the water-retentive material without affecting the physical strength of the support sheet or the packaged product. In a preferred embodiment, the support sheet is made of paper or a polymeric material, such as polyethylene, and the water retentive material is formed from polyacrylonitrile, or an acrylonitrile based co-polymer, treated with an alkaline aqueous solution of aliphatic or cycloaliphatic monofunctional or polyfunctional alcohols that have melting points greater than or equal to 110° C. The packaging material is ideal for the packaging of moisture sensitive foods, such as cheese.

I claim: 
     
       1. A material, in sheet form, for the packaging of a moisture-sensitive food, such as a cheese, comprising in combination at least one support sheet and a coating of at least one water retentive material on said support sheet, said support sheet being selected from the group consisting of paper, cellulose films, regenerated pure cellulose polymers, polyethlylene, polypropylene, polyvinyl chloride and polyester; and said water-retentive material being a water-retentive resin selected from the group consisting of polyacrylonitriles or acrylonitrile-based copolymers, treated with alkaline aqueous solutions of aliphatic or cycloaliphatic mono or polyfunctional alcohols having melting points greater than or equal to 110° C. solutions of aliphatic or cycloaliphatic mono or polyfunctional alcohols of a melting point greater than or equal to 110° C. 
     
     
       2. A material according to claim 1, wherein the support sheet comprises a single layer. 
     
     
       3. A material according to claim 1, wherein the support sheet comprises a plurality of layers. 
     
     
       4. A material according to claim 1, wherein the material also comprises at least one aluminum foil layer connected to a support sheet. 
     
     
       5. A material according to claim 1, wherein the support sheet is gas and/or water vapor proof. 
     
     
       6. A material according to claim 1, wherein the support sheet is permeable to gases and/or water vapor. 
     
     
       7. A material according to claim 1, wherein the water retentive material is incorporated in the support sheets. 
     
     
       8. A material according to claim 1, wherein the water retentive material is superimposed on the support sheet. 
     
     
       9. A material according to claim 1, wherein the connecting means for connecting the water retentive material to the support sheet has an adhesive power and is contained in the water retentive material. 
     
     
       10. A material according to claim 1, wherein the connecting means for connecting the water retentive material to the support sheets has an adhesive power and is formed by an adjuvant.